There is a min throttle angle in the electronic airflow tab but possibly can just lower Decel Max Rate in the Idle -> Torque tab to not have it try to rev down quicker than it's able to catch itself at the target idle RPM. Maybe allowing more torque correction or commanding higher torque will prevent it from trying to close the throttle quite as much as well...
Again these are guesses so if it doesn't work don't think something must be off.
At idle your intake cam moves to a higher value once the engine starts to move up. This allows the engine to idle lower. If you are using 0, 40 the minimum Idle wont go below 800 which is good.
For stability mode you can rescale the distance table and allow it to use MP 1 and 0 based on RPM. This way you can leave stability enable load max lower. you can have MP 2 be at more aggressive intake value like -10,40 then MP 1 can be 0,30 and MP 0 can be 5,10 to give a better transition back to normal fuel economy mode, since this is the way that mode will rotate the cam.
Stability.PNG
You can zero out the closed loop PID controller at that rpm/load to prevent misfire fuel trim correction.Originally Posted by 06300CSRT8
Interesting, didn't know it had a misfire fuel trim correction. Definitely was seeing some misfires, threw two P030X codes at me towards the end of my trip.
I will get back to this tuning in a few days, have not done anything more yet
I just mean fuel correction due to misfires. A misfire will show as a lean condition due to the unburnt o2 in the stream. Zeroing out the PI Controller will prevent the correction due to the intended misfires with a ghost cam tune.
Last edited by Witt; 07-29-2017 at 11:21 AM.
Thanks Witt, though I am a bit confused. the two PI controllers are for rpm error and use throttle blade adjustments and spark corrections to achieve the desired idling. They don't have any impact to fueling or fueling adjustments due to misfires, unless I am lacking in my understanding of the PI controller logic.
Fuel trims and their logic alone (transient delay) would be the only thing reacting to the misfires and bad o2 readings.
Actually maybe I missed it, are you speaking of the integral term in the Cutoff, DFCO tab?
Should be under Fuel -> Open and Closed Loop -> PI Controlller
I won't be near a PC until tonight to screenshot and highlight.
Got it thanks!
fuel PI.PNG
These tables they are based on RPM and load.
The proportional in the idle area is high and the integral is low.
Proportional is high as fuel and air quantities are low making the sensors job more difficult. This gives what error is detected more weight in the closed loop adjustment.
Integral is low as air flow rates are low so transport delay will be greater. This means the "area under the curve" would be greater as the time it commands back and forth between rich and lean is increased and therefore integral would have more power of adjustment. it is lowered to prevent this.
exactly what tables need to be modified in the cam timing tabs?
when I see the 0/40 spilt between intake and exhaust is that being entered in the ivo,evo in the op tab or under the mapped point tabs, or is that in the cam phasing one. I'm confused. thank you from a newbe
Anyone ? I am Just confused on the subject
In the mapped points tables
With the idle and load areas zeroed out in the PI CONTROLLER is it normal for the misfire to show up as a very lean condition on the dash? Dash shows idle between 15-17 afr at idle and my lambda pod on ngauge is 1.2-1.43 at idle.
You can change ivo/evc in mapped points 0 and 1 to both contain ivo 0 and evc 40. On your vct fuel economy distance table change your first two rpm to 750, 1000. If it's not already. Then highlight top left 2x2 cells. 750 and 1000 and your two lowest loads, change the cell values to 0
You're retarding the exhaust 40 degrees longer than what its used tuned for at idle airflow. The air flowing in is the same but the exhaust is staying opened much longer. Maybe fuel/air is escaping while the exhaust I'd opened. It's the opposite of EGR.
Or maybe it's the misfire. I always made changes to the fuel trims when messing with vct.
When you say you make changes to the fuel trim when you make changes in the vct how exactly are you doing that?
I could be wrong. The maf is reading the intake air. But things inside the motor are changing, cylinder pressures changing, valve events changing, overlap, scavenging at idle. Fuel trims, MAF vs Period.
like how are you adjusting them at idle? is this the tab your a talking about zero the highlighted out?IMG_6845.jpg
Yes. Remember that Best Fuel Economy distance tables point to Fuel Economy Mapped Points which point to the IVO/EVC angles. (My idle uses Optimal Stability, I suppose 2015+ are different?)
Log your load @ idle, put the A/C on, etc. Make sure you modify the cells appropriate to your load and RPM conditions where you want the modified cam timing to occur (you may need to select more cells in the 750rpm column to cover the load).
Also, remember that if you use a lot of overlap, transitioning out of high overlap to low overlap will cause stalling issues, etc, so you will have to adjust accordingly. Trial and error my friend
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